I own an H&R 732 as well as a 929. Both with the square butts. Theyre the same size. Tyler and BK only reference S&W frames as well as Colt. I assume they are equivalent to a K frame but it could be L, J even or Colt D. They've suggested the size J fits an H&R topbreak, which seems to be...

I have a H&R 732 with a 4" barrel .32 S&W Long. I want to put a 2 1/2" barrel that just says 32 cal. Is it the same diameter and will it work? What .32 bullet would NOT fit?